Steam pressure question

geemalar · February 27

Hi all, looking for some additional guidance………..I had checked in a month or so ago. The good news is warmer weather is coming, and my single pipe steam system works great. My main concern is water loss……..when it’s really cold here in northern NJ (5 degrees overnight, teens during the day) I find myself having to add about a pint of water every 2 to 3 days. I’ve been able to locate an angle shut off valve below one radiator that has a pretty decent leak, so that’s a start once the heating system is over.

Peerless boiler that’s about 8 years old. Late last summer I had to replace my boiler sediment drain valve (at the bottom of the boiler) It had a slow leak and I had to really tighten it way too tight to get it to stop. At the same time, since I had the drain the boiler, I flushed the boiler and return line. I did not clear the pressure tool pigtail, as I knew nothing about that at that time. In my original note someone noticed that my 0-30 psi pressure gauge was stuck at 9 psi. I’ve been continuously tapping on it, hoping that I could get the gauge to register something. Eventually I got it to drop to 2psi, but not any lower. I plan to fit a 0-3 psi gauge in conjunction with a new pigtail after the heating season is over. Now when the boiler is running, the gauge goes up to 5 psi. So I’m not really sure what the actual pressure is (if the gauge is reading correctly) but it does appear that the system is running too much pressure.

I also know that I need to skim my boiler. My sight glass is clear at the water line and below, but above the water line it’s got what appears to be oily residue. I had forgotten that when I had an additional bedroom built, I had a radiator line extended approximately 12 feet. I’m fairly confident that the residue in that additional piping has finally made its way down to the boiler.

So besides my leaking angle valve, I appear to have a pressure issue. Am I at the point that I need to focus on the pressuretrol to correct this issue.

I get no noise whatsoever from my system. It heats, it’s quiet, I get no water spitting out of any vents, but I know it needs some attention related to the pressure. Any recommendations at this point would be appreciated.

ethicalpaul · February 28

you have the plan already.

clean the pigtail and install a low pressure gauge. Then you’ll know how things are performing.

No need to wait until summer, might as well have a look during spring.

You live in NJ so if you want, I can teach you how. See my link below.

geemalar · February 28

I’ll start by getting the 0-3 psi gauge, a new pigtail and appropriate fittings to assemble the gauge and T it in on the pigtail line.

ethicalpaul · February 28

And yes I see you are concerned about oil. Skimming never hurts, but if your water line is pretty stable during steaming you can put it off until it's convenient.

geemalar · February 28

Water line barely fluctuates as the system is running, it’s just that the water below the water line is clear yet the air space above the water line has a lot of contaminants stuck to the glass.

ethicalpaul · February 28

Yes I agree that is a sign that there is oil on your water, but it's not enough to cause surging, otherwise your water level would drop by a very noticeable amount.

EBEBRATT-Ed · February 28

@geemalar Use a brass pigtail …not steel and all brass fittings. Put the low-pressure gauge on. Also replace your 0-30 gauge as well.

If it was me I would put a 1/4" ball valve or petcock under the new lo pressure gauge and keep it shut off unless your checking the pressure….it will last longer.

And don't worry about the lack of pressure. The lower it is the better. As long as the house heats and is quiet that is 90% of the battle.

mattmich · February 28

Regarding the residue:

"Yes I agree that is a sign that there is oil on your water"

It's more that it's a sign there WAS oil on your water at some time.

I have the same issue, but the last time I skimmed, I couldn't really see anything swimming on top of the water. Certainly not the way it looked the first few times I skimmed after installing the boiler.

The sight glass is installed in such a way that it can be removed and cleaned without draining the boiler. Yes you can do it now, but like you, I"m superstitious about touching a system I need to run every day, so I'm putting it off until April.

See my DIY thread, last couple of pages, for the installation of a low-pressure gauge above a shutoff valve that protects the gauge.. You find it after clicking on my username. My Peerless runs at a fraction of 1 PSI even if I try to provoke a higher pressure, so I find 5 PSI hard to believe. My 30 PSI gauge has never once budged off zero.

cheers -matt

geemalar · February 28

@EBEBRATT-Ed

My concern isnt lack of pressure……..its having too much pressure. My 0-30 psi gauge was stuck at 9 earlier this season, Ive been tapping it lightly trying to get it to break free. Not thinking that would actually work, eventually it did break free. I finally got it to drop back down to zero when the boiler stopped running for a while. I now get a reading of 6 psi during full heat. My understanding is that is too much pressure for my single pipe system.

I’m going to try and clean the pigtail today, as I notice the end connected to the boiler is hot and the opposite end at the pressuretrol is significantly cooler.

mattmich · February 28

There is no 'flow' through the pigtail, since it's a dead end. It exists so the gauge does not come into contact with steam.

And yes, you should have NO measurable pressure on your 30 PSI gauge. The fact that it sticks is a sign it's not working right, but the fact that you can tap it, get it down, and it rises when the boiler is running is a sign of problems. Do you know the size of your boiler and the size of your installed radiation (EDR)? Domestic single pipe steam should run at less than 1 PSI… it'd be good to figure out what's going on.

Your Pressuretroll should be cutting out and back in to regulate pressure; never heard of one regulating up to 9 PSI. Something doesn't add up. Pictures of the boiler, the piping, and the Pressuretroll might help the pros here to help.

geemalar · February 28

The reading on the pressure gauge in this picture

is from when I took these pictures about 2 months ago. Now it goes up to 6psi.

AFA the pigtail, is it common that the output end is hot enough so I can barely hold my finger on it, yet the end at the pressure troll is lukewarm.

geemalar · February 28

Here’s some of the return lines…..

geemalar · February 28

And to clarify…….the pressure gauge drops down to zero on its own now, I no longer have to tap it to make it work. I also understand that the pigtail is a dead end and technically has no flow through it, but if it was NOT clogged shouldn’t both ends be relatively close in temperature. They are significantly different to the touch.

Thanks again to everyone who’s offered their assistance.

mattmich · February 28

If your gauge is anywhere near accurate, I guarantee your pigtail is plugged. Your Pressuretroll should cut out long before you get to 5 PSI. Your cut-in appears properly set to about 1 PSI.

That boiler is a 63-04L or 63-04, depending on how many burner tubes are underneath; 5 or 6, respectively.
Given the single tapping used vs. the installation manuals requrirements , you should have the lower-fired 63-04L with 5 burner tubes.
The gas input is 147.5 or 177 per the maunufacturer; the net steam ratings are 383 or 458.
It'd be good to know roughly how many square feed of radiation this serves.

geemalar · February 28

I just counted, it’s got 5 burners underneath. Let me start by removing and cleaning or replacing the pigtail with a new brass one and take it from there.

After that I’ll start into investigating getting the EDR of what we have.

Like I said in my OP…….my heat works great, not a peep of clanging or hissing anywhere……..so I have that going well for me. I just know, from reading on this site, that it can be better.

ethicalpaul · February 28

I also understand that the pigtail is a dead end and technically has no flow through it, but if it was NOT clogged shouldn’t both ends be relatively close in temperature. They are significantly different to the touch.

This is expected and is the whole point of having it. Regardless of whether it's clogged, there is a water trap in there that will prevent steam from going past it.

The heat that conducts from the boiler itself dissipates rapidly into the air leaving the pressuretrol end of the pigtail cool to warm.

It's more that it's a sign there WAS oil on your water at some time.

Maybe. I'm not sure how you can tell from looking at oil in a gauge glass if there is still oil on the water in the boiler. I can say that when I have skimmed, it tends to clean the inside of the gauge glass and so I stand by my observation that an oil slick in the gauge glass is reason to consider skimming.

EBEBRATT-Ed · February 28

tapping the gage that make the needle move is a 100% sign that the gauge is bad or the pigtail is plugged. probably the gauge.

techforlife · March 1

Bad gauge. If you had 5 psig steam pressure you would know it. Spitting vents, banging, etc.

ethicalpaul · March 1

5 psi does not cause banging in a one pipe system but I agree you can never trust a factory 0-30psi gauge

techforlife · March 1

5 psi steam pressure will cause water to stack up about 11 ft. above the water line in return piping ("A" dimension). Chances are the water will be up into the main if not the first floor by then, so there will be plenty of banging.

mattmich · March 1

Now you've done it! I know Paul has warmed up to this subject before.

I will say that "5PSI" to first order means "5PSI everywhere in the system," in which case nuthin' stacks anywhere.

If you assume that it's 5 PSI inside the boiler, then you have to explain while it's just atmospheric pressure in the returns… what's keeping the steam for pressurizing the mains?

Jamie Hall · March 1

I don't recall whether this is a one pipe or a two pipe system. If it is a one pipe system, the @mattmich is correct, since in a one pipe system there are no returns at atmospheric pressure. All that will happen is that valves and vents will be overpressured, and leak or spit or hiss or otherwise misbehave.

If this were a two pipe system, in which the returns are at atmospheric pressure, then yes you would get water stacked up into the dry returns — and things would be very unhappy.

ethicalpaul · March 1

https://forum.heatinghelp.com/discussion/comment/1845906#Comment_1845906

It's a one pipe system and no pressure will cause water to stack up. Here's my video that proves it if you are interested. The reason is because the same pressure that is pushing water out of the boiler is also existing at the far end of the main and is pushing the exact same amount in the other direction.

https://youtu.be/6ZLg3fqU1MQ

techforlife · March 2

Pressure creates altitude of water column. We also have to consider application. We know that many jobs are not set up optimally. As the water leaves the boiler, the auto feeder, if so equipped, may not be a VXT. Imagine that! As the pressure builds, make up water is added to satisfy the water line until it stacks up in the return. I have seen this so many times I can't tell you.

Dave in QCA · March 2

Very interesting video, but it is not any different that I would have expected it to be. If you read information about Dimension A, it will discuss that factors that you are measuring. Most of the dimension A is a safety allowance. The pressure at the inlet of course is going to be the same as the steam outlet in the boiler. Any difference that may exist causing the water to back up (dimension A) will be small and it is caused by the steam that is being consumed in the radiators. You have to remember that steam is traveling fast down the main and a portion is going into each radiator and coming back out as condensate. As you get to the end of the main, it will produce a slightly lower pressure causing a slight backup of condensate. But back at the boiler, the equalizer pipe will do nothing to effect this. I'm not sure anyone ever said it did. It is obvious to me that the equalizer pipe has nothing to do with pressure out at the end of the system.

What the Equalizer Pipe does do is return boiler water that flows with the steam into the header. The header is a steam and water separator, and the equalizer pipe allows that to flow into the boiler at a point that is assured to be equal pressure with the outlet. The equalizer, perhaps a misnomer, assures that the pressure at those two points connecting to the boiler is the same. Seems like it would be anyway. Maybe it would. But it is agreed that the equalizer has little to do with the conditions way out at the end of the system. You still have to worry about Dimension A.

ethicalpaul · March 2

Dimension A is the dimension at the end of the main down to the waterline, right? You don't have to worry about that.

Thanks for your reply though, you are in a very small club of people who saw in my video what happened and noted it.

And no water goes up to the header unless the water quality is real bad. I've got other videos that show that too.

geemalar · March 2

So I’m kind of on hold right now AFA removing the pigtail. I tried to unscrew it and it would not budge without using excessive force. I also could not get the pressuretrol to unscrew from the top of the pigtail. I guess that’s what I get for not unscrewing it and checking it regularly every season. Now I know……

We’re in a short cold spell right now, so I’m holding off until it gets warmer this coming week.

FWIW my pressuretrol dial shows the number 1 ………but not knowing if the pigtail is clear kind of makes the setting irrelevant right now.

Steam pressure question

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